1. Field of the Invention
The present invention relates to fluid consumption systems in the home and commercial environments. More particularly, the invention relates to automated controls and monitoring of fluid-based systems employing methods and systems for detecting, communicating, and preventing operational failures.
2. Description of the Related Art
There are various water-consuming fixtures, appliances, and systems in both residential and commercial installations. Typical water-based systems include sinks, toilets, dishwashers, washing machines, water heaters, lawn sprinklers, swimming pools and the like. For example, hot water tanks include a heating element located at the bottom of the tank, with a hot water outlet pipe and a make-up water inlet pipe connected through the top of the tank. In water tanks a thermostat is generally included for setting the desired temperature of the hot water withdrawn from the tank, and typically a blow-out outlet is connected through a pressure relief valve to allow hot air, steam and hot water to be removed from the tank through the relief valve when the pressure exceeds the setting of the relief valve. The relief valve may be periodically operated for relatively short intervals during the normal operation of the hot water tank. This allows bubbling steam and water to pass through the relief valve for discharge. Once the pressure drops below the setting of the relief valve, it turns off and normal operation of the hot water tank resumes.
After a period of time, however, mineral deposit buildup and corrosion frequently take place in relief valves and the like, as a result of these periodic operations. In time, such corrosion or scale build up may impair operation. When this occurs, the possibility of a catastrophic failure exists. In addition to the possibility of high pressure explosions taking place in water tanks, other conditions can also lead to significant damage to the surrounding structure. As hot water tanks age, frequently they develop leaks, or leaks develop in the water inlet pipe or hot water outlet pipe to the tank. If such leaks go undetected, water damage from the leak to the surrounding building structure results.
U.S. Pat. No. 5,240,022 to Franklin discloses a sensor system, utilized in conjunction with hot water tanks designed to shut off the water supply in response to the detection of water leaks. In addition, the Franklin patent includes multiple parallel-operated sensors, operating through an electronic control system, to either turn off the main water supply or individual water supplies to different appliances, such as the hot water heater tank.
U.S. Pat. No. 3,154,248 to Fulton discloses a temperature control relief valve operating in conjunction with an over heating/pressure relief sensor to remove or disconnect the heat source from a hot water tank when excess temperature is sensed. The temperature sensor of U.S. Pat. No. 4,381,075 to Cargill et al. is designed to be either the primary control or a backup control with the pressure relief valve. Three other U.S. patents, to Lenoir, U.S. Pat. No. 5,632,302; Salvucci, U.S. Pat. No. 6,084,520; and Zeke, U.S. Pat. No. 6,276,309, all disclose safety systems for use in conjunction with a hot water tank. The systems of these patents all include sensors which operate in response to leaked water to close the water supply valve to the hot water tank. The systems disclosed in the Salvucci and Zeke patents also employ the sensing of leaked water to shut off either the gas supply or the electrical supply to the hot water tank, thereby removing the heat source as well as the supply water to the hot water tank. U.S. Pat. No. 3,961,156 to Patton utilizes sensing of the operation of the standard pressure relief valve of a hot water tank to also operate a microswitch to break the circuit to the heating element of the hot water tank.
While the various systems disclosed in the prior art patents discussed above function to sense potential malfunctioning of a hot water tank to either turn off the water supply, the energy supply, or both, to prevent further damage, none of the systems disclosed in these patents are directed to a safety system for monitoring potentially damaging pressure increases in the hot water tank in the event that the pressure relief valve malfunctions. This potential condition, however, is one which is capable of producing catastrophic damage to the structure in the vicinity of the hot water tank.
U.S. Pat. No. 5,428,347 to Barron shows a water monitoring system with minimal expansion and protection capabilities. The input and outputs (I/O) offered by the system limit the number of water appliances individually protected. The Barron device was designed such that a normal installation would use a single control unit. The number and types of inputs suggest it was designed primarily to protect a single water heater, and to act as an external control unit for an air conditioner. A number of auxiliary devices could be protected using an auxiliary water sensor input. Outputs provide for control of a hot water solenoid, a cold water solenoid, three alarm signals for external buzzers or bells and an optional external air conditioner control unit. This requires that the unit control be a single standard 24 vac water control valve for the main hot water in feed and the main cold water in feed line. Thus, it can cut off the power to the unit that tripped the alarm. No matter which sensor is triggered, it appears that the unit can only cut off the main water in feed line(s) to the home and can only remove power from the unit plugged into it. However, the unit does not have a one-to-one correspondence between a sensor and a control valve. The valve control outputs are wired such that if any one of the units sense a water leak, it could close the valves.